imgur_enrich_comments.user.js

// ==UserScript==
// @name        imgur_enrich_comments.user.js
// @namespace   foo
// @include     http://imgur.com/*
// @version     1
// @grant       none
// ==/UserScript==


function patch_comment(node, data){
  var jnodes = $(node).find(".author span");
  var points = jnodes.get(1);
  var date = jnodes.get(3);
  points.title = "+ " + data.ups + " / - " + data.downs;
  date.title = data.datetime;
  $(points).tipsy();
  $(date).tipsy();
}
// patch all existing comments ...
$(".caption").each(function(){ patch_comment(this, Imgur.InsideNav._instance._.captionInstance._.captions[imgur._.hash].set[this.getAttribute('data-id')]); });
// and register for dom changes to patch the new ones.
observer = new MutationObserver(function(mutations) {
  var captions = Imgur.InsideNav._instance._.captionInstance._.captions[imgur._.hash].set;
  for(var i=0; i < mutations.length; ++i){
    for(var j=0; j < mutations[i].addedNodes.length; ++j){	
      var node = mutations[i].addedNodes[j];
      if( node.className === undefined )continue;
      if( node.className.indexOf("comment") == 0 || node.className.indexOf("children") == 0){
        $(node).find('.caption').each(function(){
          patch_comment(this, captions[this.getAttribute('data-id')]);
        });
      }
    }
  }
});
var target = document.querySelector('body');
observer.observe(target, { subtree: true, childList: true });